A study on the microstructure and electrochemical characteristic of TiTa alloys and the nitride thin films

• Main Authors: Ying-JungLu, 呂瓔融
• Other Authors: Chen-Kuei Chung
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/13819155711667048189

碩士 === 國立成功大學 === 機械工程學系 === 102 === Binary transition metal nitride films such as titanium nitride (TiN) and tantalum nitride (TaN) have been attracted by it excellent properties. The combination of TiN and TaN is expected to create a multi-functional material. The ternary titanium tantalum nitride films with different N2/(Ar+N2) gas flow ratios (0, 5, 10, 20%) are deposited by dc reactive magnetron co-sputtering on Si (100) substrates. The effect of increasing N2 flow ratios on the microstructure, morphology, electrical properties, and electrochemical properties of the Ti-Ta-N films are investigated by means of X-ray diffraction, scanning electron microscopy (SEM), four-probe method, potentiostatic, and electrochemical impedance spectroscopy, respectively. The microstructure of TiTaN films is more stable than TiN or TaN films. The results show that the TiTa alloy film exhibits low resistivity and positive temperature coefficient of resistance (TCR) while the TiTaN films show higher resistivity and negative TCR. The change of resistivity of TiTaN films with increasing nitrogen flow ratio is more linear than TiN or TaN. The TiTa alloy film exhibited the best corrosion resistance. The SEM image of TiTaN films showed columnar microstructure while TiTa film showed large granular and flat morphology. Our studies suggested that the single phase structure is benefit to electrical properties while the amorphous-like structure and denser morphology are benefit to corrosion resistance.